This work investigated the potential of generating biogas from mono-digestion of various substrates such as food and fruit waste (e.g., durian shell, dragon fruit peel and pineapple peel) and co-digestion in different combinations of a co-substrate as food waste as well as different types of fruit waste (durian shell, dragon fruit peel and pineapple peel). The mixture of food waste and fruit waste ratio varied as follows: 75:25, 50:50 and 25:75, which was based on weight. The batch experiments were carried out using 125 ml anaerobic digesters and were incubated for 50 days. For a mono-substrate, food waste produced the highest amount of methane gas (60.63 ± 1.02 ml/gvs) followed by durian shell (34.93 ± 1.30 ml/gvs), pineapple peel (31.70 ± 1.60 ml/gvs), and dragon fruit peel (30.12 ± 1.20 ml/gvs), respectively. The highest amount of methane gas came from food waste mixed with durian shell (FW75:D25), and it was on a higher level than food waste mixed with dragon fruit peel (FW75:DF25) and pineapple peel (FW75:P25). The highest methane gas production of co-digestion which was observed at the proportion of food waste and durian shell was 75:25 and produced higher content of methane gas than the highest methane gas production of mono-digestion (food waste) according to the high organic compound and optimum pH value in the system. The results showed that the co-digestion of durian shell and food waste improved methane production and reduced the startup time compared with their mono-digestion. On the other hand, pineapple peel was not suitable for co-digestion with food waste due to a decreasing pH value in the system.
This study investigated the possibilities of improving biogas yield from anaerobic digestion of refinery activated sludge (RAS) by optimizing the food to microorganism (F/M) ratio. Different F/M ratios of 0.25, 0.50, 1.00 and 2.00 were studied. The highest biogas production (147.98±7.40 ml/gvs), methane production (51.41±1.78 ml/gvs) and methane content (42.00±5.90%) were obtained from the F/M ratio of 1.00 followed by 0.50, 0.25 and 2.00, respectively. The phytotoxicity of biosolids that came from anaerobic digestion was also evaluated using three different types of seed (Vigna radiata, Brassica rapa and Lycopersicon esculentum) during this process. Increasing amount of RAS via increasing of the F/M ratio (0.25-1.00) stimulated plant development (GI>100) and reduced the phytotoxicity of RAS.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.